43 replies to this topic

[JSE]

charliechitlins, on 17 January 2012 - 06:50 PM, said:

Thanks...good call on the oil in the cyl.
It has been sitting awhile and would be dry.
The difference in compression with throttle open is, I think, due to the amount of air being let in.
The carb was empty.
And...I have a new plug installed and set to .3mm, as per your recommendation...I just have to find the time to get the tank on and give it a few kicks.
This weekend, after doing all 4 brake pads and rotors on my old car, I just didn't have the energy to spin any more wrenches.
Thanks.

Charlie, compression testing (and comparison to spec. readings) is always taken with the throttle WFO.

Jon

[charliechitlins]

JSE, on 18 January 2012 - 12:39 AM, said:

Charlie, compression testing (and comparison to spec. readings) is always taken with the throttle WFO.

Jon

I know that and YOU know that....but I have had the contrary insisted to me on several occasions.
So I try to keep everybody happy by giving both readings.

[JSE]

charliechitlins, on 18 January 2012 - 07:59 PM, said:

I know that and YOU know that....but I have had the contrary insisted to me on several occasions.
So I try to keep everybody happy by giving both readings.

O.k., that makes sense. I just can't figure out what the performance parameters of a compression
test with the throttle closed would be. Regardless, you've made ME happy....

I agree with tankygsy, in that it should do something even with 70 PSI. It would be hard to start
but would at least run crappy I'm guessing. Maybe it's possessed and you need a priest............

What'ca think, try using something like WD40 as a starting fluid?

Jon

[steve]

My goodness what a pain this has turned into for you. Reading through it sure looks like you know what you're talking about and I would imagine that if it was something simple you'd have found it long ago.
So where to go now? Basics... Compression, fuel, spark.
I reckon the compression you have should be enough.
Fuel, well you're getting a wet plug so should be ok but to make sure give her a squirt of wd40 and a few kicks. That'll at least rule it out.
So that leaves spark...My first thought as was yours is flywheel key. Mainly due to how you described it stopping the last time it ran (unless it nipped up) Yes it sparks but is it in the right place? You've checked the key though so could electrical gremlins cause a timing problem?
I once had a 96 Beta that ran backwards if the connector to the black box got damp. Pull all the wires, clean and check earths etc... but better still see if you can get the loan of another bike and swap some bits over.

Good luck and keep us posted, it's bugging me!

[ausy300pro]

Have a friend who had a gasser (coincidentally) that did a very similar thing, that farted about and then refused to start, turned out to be a duff ignition, if I remember right it was either stator or pick up which was throwing the spark all over the place, this could well be whats happening with yours, if you don't get it going soon try someone elses stator and pick up (assuming you have a mate with a similar age gasser), my mates went down a week after being loaned out and coming back with igniton full of water, has yours been left with water in ignition ?

[copemech]

Seems I do recall bikes that stopped running due to lack of compression. Kind of a wierd deal and many moons ago, but his numbers do not look good! I figure you could push it through by hand if his guage is working!

I have never owned anything like that, and reall only recall one that just gave out!

[HAM2]

charliechitlins, on 16 January 2012 - 08:03 PM, said:

OK......
I drilled the starter jet a little because I wanted to feel like I was accomplishing something......

Man, you're in a dark place if you're starting to think and act like me

[charliechitlins]

AND...when it did start and run, it ran beautifully.
A shocking amount of bottom end...and that's with my main point of reference being a Sherco 2.9.

Oooohh...just remembered another symptom...the last couple times it ran, it revved very high on start-up.
I suspected an air leak.
But it calmed down upon closing the enrichener.
Thanks to everybody for your help.
I wish I had more time to keep on top of it.
Weeks can go by before I can carve out a few minutes to work on this thing.
I have 2 paid jobs ahead of mine.
A '48 Indian Chief and a 250 Ninja.
My workshop is a strange place!

[lineaway]

70 PSI sure seems low I`d bet on a stuck ring on the intake side of things. Seen this a lot recently trying to keep my nephews yz`s running. At least it`s a winter project. Might pull my bike out today,just had the snow melt off finally.

[Baldilocks]

on my 05 250 GG i ended up borrowing a mates CDI Box and then Stator plate, still had a spark but would not go. Eventually I removed the cloth I had put in the carb and forgot to take out when putting the filter box back on...... and it started !

so have you blocked off the air filter / carb / reeds and left somthing in or left the pilot jet on the bench (did that at the SSDT) ?

If you dont reply i'll know its a yes...

[Dan Williams]

70 PSI is really low. That's gotta be far below operational pressure. I get a usual reading of 140 on my Betas when they're healthy. Could be blockage of the exhaust, broken baffle or such. Broken reed or something stuck in the intake as mentioned before.

The mention of ether makes me nervous. In a four stroke where the oil doesn't work up to the crown it's no big deal. On a two stroke it can cause momentary dry spots in the cylinder/piston interface as it cleans off the residual oil. I'd limit the ether application to last resort.

As for ring sticking it sometimes is carbon buildup in the grooves rather than piston scrapes.

Edited by Dan Williams, 20 January 2012 - 07:56 AM.

[big_G_uk]

if you have checked the wood draft key and all is in order in the timing depo,

i would say its the crank seals!!

sounds spot on symptoms after reading what you have said,
providing when you strip the barrel off and all is in order an the piston an rings are ok dont worry if there is some wear,
ive had two strokes run with a chunk of piston missing!! didnt eaven no there was a problem lol,
but if all is in order there i would split it and set to changing the crank seals

let me no if im wrong or right!!

[charliechitlins]

Well...a few minutes of work reveals a pretty nastily scuffed piston and barrel and rings seized in the lands.
Off we go.
I'm assuming that boring and plating is more economical than a new barrel....

[copemech]

charliechitlins, on 01 February 2012 - 03:00 AM, said:

Well...a few minutes of work reveals a pretty nastily scuffed piston and barrel and rings seized in the lands.
Off we go.
I'm assuming that boring and plating is more economical than a new barrel....

A 225 kit from RYP is about the same!!! Go for it!